kernel: mark nvmem as hidden, it is only used as a library for other modules

Signed-off-by: Felix Fietkau <[email protected]>

package/kernel/linux/modules/other.mk

@@ -129,6 +129,7 @@ define KernelPackage/nvmem
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Non Volatile Memory support
   KCONFIG:=CONFIG_NVMEM
+  HIDDEN:=1
   FILES:=$(LINUX_DIR)/drivers/nvmem/[email protected]
 endef